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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/VisibleFinalState.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
#include "Rivet/Projections/DressedLeptons.hh"
namespace Rivet {
/// @brief Differential cross section of Z boson production in association with jets at 13 TeV
///
/// @note Code copied from CMS_2015_I1410737 and adapted by P. Gras to CMS-SMP-16-015,
class CMS_2018_I1667854 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2018_I1667854);
/// Book histograms and initialise projections before the run
void init() {
// Get options from the new option system; defaults to combined e+mu
_mode = 2;
if ( getOption("LMODE") == "EL" ) _mode = 0;
if ( getOption("LMODE") == "MU" ) _mode = 1;
if ( getOption("LMODE") == "EMU" ) _mode = 2;
// Projections
FinalState fs;
VisibleFinalState visfs(fs);
VetoedFinalState fs_notaudecay(fs);
fs_notaudecay.addDecayProductsVeto(PID::TAU);
fs_notaudecay.addDecayProductsVeto(-PID::TAU);
IdentifiedFinalState bareMuons(fs_notaudecay);
bareMuons.acceptIdPair(PID::MUON);
declare(DressedLeptons(fs, bareMuons, /*dRmax = */0.1,
Cuts::abseta < 2.4 && Cuts::pT > 20*GeV), "muons");
IdentifiedFinalState bareElectrons(fs_notaudecay);
bareElectrons.acceptIdPair(PID::ELECTRON);
declare(DressedLeptons(fs, bareElectrons, /*dRmax =*/ 0.1,
Cuts::abseta < 2.4 && Cuts::pT > 20*GeV), "electrons");
FastJets jets(visfs, FastJets::ANTIKT, 0.4);
declare(jets, "jets");
// Histograms
book(_h_excmult_jets_tot, 1, 1, 1);
book(_h_incmult_jets_tot, 2, 1, 1);
book(_h_zpt1, 3, 1, 1);
book(_h_leading_jet_pt_tot, 4, 1, 1);
book(_h_second_jet_pt_tot, 5, 1, 1);
book(_h_third_jet_pt_tot, 6, 1, 1);
book(_h_leading_jet_y_tot, 7, 1, 1);
book(_h_second_jet_y_tot, 8, 1, 1);
book(_h_third_jet_y_tot, 9, 1, 1);
book(_h_ht1_tot, 10, 1, 1);
book(_h_ht2_tot, 11, 1, 1);
book(_h_ht3_tot, 12, 1, 1);
book(_h_ptbal1, 13, 1, 1);
book(_h_ptbal2, 14, 1, 1);
book(_h_ptbal3, 15, 1, 1);
book(_h_jzb, 16, 1, 1);
book(_h_jzb_ptHigh, 17, 1, 1);
book(_h_jzb_ptLow, 18, 1, 1);
}
/// @brief Z boson finder
///
/// @note We don't use the standard ZFinder class in order to stick to
/// the definition of the publication that is simpler than the ZFinder algorithm.
///
/// @param leptons pt-ordered list of electrons or muons from which to build the Z boson
std::unique_ptr<Particle> zfinder(const Particles& leptons) {
if (leptons.size() < 2) return 0;
if (leptons[0].charge()*leptons[1].charge() > 0) return 0;
std::unique_ptr<Particle> cand(new Particle(PID::ZBOSON, leptons[0].mom() + leptons[1].mom()));
if (cand->mass() < 71.*GeV || cand->mass() > 111.*GeV) return 0;
return cand;
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Get leptons
const Particles& muons = apply<DressedLeptons>(event, "muons").particlesByPt();
const Particles& electrons = apply<DressedLeptons>(event, "electrons").particlesByPt();
// Look for Z->ee
std::unique_ptr<Particle> z = zfinder(electrons);
const Particles* dressedLeptons = 0;
if (z.get() != nullptr) {
dressedLeptons = &electrons;
if (_mode == 1)
vetoEvent;
} else { // look for Z->mumu
z = zfinder(muons);
if (z.get() != nullptr) {
dressedLeptons = &muons;
if (_mode == 0)
vetoEvent;
} else { // no Z boson found
vetoEvent;
}
}
// Cluster jets
const FastJets& fj = apply<FastJets>(event, "jets");
const Jets& jets = fj.jetsByPt(Cuts::absrap < 2.4 && Cuts::pT > 30*GeV);
// Remove jets overlapping with any of the two selected leptons
Jets goodjets = filter_discard(jets, [dressedLeptons](const ParticleBase& j) {
return deltaR(j, (*dressedLeptons)[0]) < 0.4 || deltaR(j, (*dressedLeptons)[1]) < 0.4;
});
// Compute jet pt scalar sum, H_T:
double ht = sum(goodjets, [](const ParticleBase& j){return j.pT();}, 0.);
// Fill jet number integral histograms
_h_excmult_jets_tot->fill(goodjets.size());
/// @todo Could be better computed by toIntegral transform on exclusive histo
for (size_t iJet = 0; iJet <= goodjets.size(); iJet++ )
_h_incmult_jets_tot->fill(iJet);
if (goodjets.size() < 1) return;
// Hadronic recoil:
FourMomentum recoil;
for (const auto& j: goodjets) {
recoil += j.momentum();
}
// Jet-Z balance = |recoil_T| - |pt(Z)|
double jzb = recoil.pT() - z->pT();
// pT balance:
double ptbal = (recoil + z->momentum()).pT();
// Fill leading-jet histograms
_h_zpt1->fill(z->pT());
const Jet& j1 = goodjets[0];
_h_leading_jet_pt_tot->fill(j1.pT()/GeV);
_h_leading_jet_y_tot->fill(j1.absrapidity());
_h_ht1_tot->fill(ht/GeV);
_h_jzb->fill(jzb/GeV);
if (z->pT() > 50*GeV) {
_h_jzb_ptHigh->fill(jzb/GeV);
} else {
_h_jzb_ptLow->fill(jzb/GeV);
}
_h_ptbal1->fill(ptbal/GeV);
// Fill 2nd jet histograms
if (goodjets.size() < 2) return;
const Jet& j2 = goodjets[1];
_h_second_jet_pt_tot->fill(j2.pT()/GeV);
_h_second_jet_y_tot->fill(j2.absrapidity());
_h_ht2_tot->fill(ht/GeV);
_h_ptbal2->fill(ptbal/GeV);
// Fill 3rd jet histograms
if (goodjets.size() < 3) return;
const Jet& j3 = goodjets[2];
_h_third_jet_pt_tot->fill(j3.pT()/GeV);
_h_third_jet_y_tot->fill(j3.absrapidity());
_h_ht3_tot->fill(ht/GeV);
_h_ptbal3->fill(ptbal/GeV);
}
/// Normalise histograms etc., after the run
void finalize() {
// Normalisation factor
double norm = (sumOfWeights() != 0) ? crossSection()/sumOfWeights() : 1.0;
// When running in combined mode, need to average to get lepton xsec
if (_mode == 2) norm /= 2.;
// MSG_INFO("Cross section = " << std::setfill(' ') << std::setw(14)
// << std::fixed << std::setprecision(3) << crossSection() << " pb");
// MSG_INFO("# Events = " << std::setfill(' ') << std::setw(14)
// << std::fixed << std::setprecision(3) << numEvents() );
// MSG_INFO("SumW = " << std::setfill(' ') << std::setw(14)
// << std::fixed << std::setprecision(3) << sumOfWeights());
// MSG_INFO("Norm factor = " << std::setfill(' ') << std::setw(14)
// << std::fixed << std::setprecision(6) << norm);
scale(_h_excmult_jets_tot, norm);
scale(_h_incmult_jets_tot, norm);
scale(_h_zpt1, norm);
scale(_h_leading_jet_pt_tot, norm);
scale(_h_second_jet_pt_tot, norm);
scale(_h_third_jet_pt_tot, norm);
scale(_h_leading_jet_y_tot, norm);
scale(_h_second_jet_y_tot, norm);
scale(_h_third_jet_y_tot, norm);
scale(_h_ht1_tot, norm);
scale(_h_ht2_tot, norm);
scale(_h_ht3_tot, norm);
scale(_h_ptbal1, norm);
scale(_h_ptbal2, norm);
scale(_h_ptbal3, norm);
scale(_h_jzb, norm);
scale(_h_jzb_ptHigh, norm);
scale(_h_jzb_ptLow, norm);
}
protected:
size_t _mode;
private:
/// @name Histograms
/// @{
Histo1DPtr _h_excmult_jets_tot, _h_incmult_jets_tot;
Histo1DPtr _h_leading_jet_pt_tot, _h_second_jet_pt_tot;
Histo1DPtr _h_third_jet_pt_tot, _h_fourth_jet_pt_tot;
Histo1DPtr _h_leading_jet_y_tot, _h_second_jet_y_tot;
Histo1DPtr _h_third_jet_y_tot, _h_fourth_jet_y_tot;
Histo1DPtr _h_ht1_tot, _h_ht2_tot, _h_ht3_tot, _h_ht4_tot;
Histo1DPtr _h_ptbal1, _h_ptbal2, _h_ptbal3;
Histo1DPtr _h_jzb, _h_jzb_ptHigh, _h_jzb_ptLow;
Histo1DPtr _h_zpt1;
/// @}
};
RIVET_DECLARE_PLUGIN(CMS_2018_I1667854);
}
|